The present invention generally relates to a method of extracting a feature of a character (including a symbol and a numeral) for character recognition, and particularly to a method of extracting a feature of a character which is affected by the font style or the size of a character to be recognized.
Currently, various character feature extracting methods have been proposed. For example, U.S. Pat. No. 4,757,551 proposes a method in which an image of a character obtained by optically scan is divided into a plurality of regions, and a histogram of direction codes is generated for each of the divided regions. However, the proposed method cannot provide feature quantities indicative of the shape of a character with high precision. For example, the proposed method is not well organized so as to extract a feature of an ornamental portion of a character.
In order to overcome the above-mentioned problem, an improved method for extracting a feature of a character has been proposed in U.S. patent application Ser. No. 191,608, the disclosure of which is hereby incorporated by reference. The improved method is less affected by the font style or the size of a character to be recognized. However, there is room for some improvements.